Hwang - Adaptive Multimode Sensing - Spring Review 2013
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This document provides an overview of Jim Hwang's Adaptive Multimode Sensing portfolio at AFOSR. The portfolio focuses on three main areas: 1) adaptive multimode sensing with an emphasis on tunable detectors that can detect properties like polarization and phase in addition to intensity and color, 2) novel infrared sensors using quantum dots, nanowires, and other novel materials and structures with the main challenge being dark current, and 3) solar cells, thermoelectric coolers, and other areas that will be deemphasized to focus the reducing budget. Several research projects within these areas are briefly described that aim to shorten the time from sensing to action and avoid being overwhelmed by data.
![11Distribution A: Approved for public release; distribution is unlimited
Single-Crystal Semimetal/Semiconductor Nano-Composites
Chris Palmstrøm (UCSB) & Kurt Eyink (AFRL/RXAN)
IncreasingErSbcomposition[001]
ρ
˔ ρ//
{110}
GaSb
ErSb
GaSb
ErSb
GaSb(ErSb)x(GaSb)1-x
(Semimetal) (Semiconductor)
•ErSb/GaSb nano-
composites grown by
molecular beam
epitaxy
•Buried conductive
layers for multicolor
infrared detectors
•THz polarizers
embedded in III-V
heterostructures](https://image.slidesharecdn.com/hwang-adaptivemultimodesensing-springreview2013-131011121347-phpapp02/85/Hwang-Adaptive-Multimode-Sensing-Spring-Review-2013-11-320.jpg)
Hwang - Adaptive Multimode Sensing - Spring Review 2013
- 1. 1Distribution A: Approved for public release; distribution is unlimited Integrity Service Excellence Adaptive Multimode Sensing Date: 07 03 2013 Jim Hwang Program Officer AFOSR/RTD Air Force Research Laboratory
- 2. 2Distribution A: Approved for public release; distribution is unlimited 2013 AFOSR SPRING REVIEW 3001B PORTFOLIO OVERVIEW NAME: Jim Hwang BRIEF DESCRIPTION OF PORTFOLIO: Adaptive Multimode Sensing LIST SUB-AREAS IN PORTFOLIO: I. Adaptive Multimode Sensing – Emphasize tunable detectors and different detection modes such as polarization and phase (in addition to intensity and color). Main challenge: phase detection. II. Novel Infrared Sensors – Emphasize novel materials and structures such as quantum dots, nano-wires, type-II superlattices, and 3D integration. Main challenge: dark current. III.Solar Cells, Thermoelectric Coolers & Others – Deemphasize to focus portfolio with reducing budget.
- 3. 3Distribution A: Approved for public release; distribution is unlimited Motivation Shorten time from sense to kill; avoid drowning in data
- 4. 4Distribution A: Approved for public release; distribution is unlimited -2 V S.I. GaAs Substrate LWIR AlGaAs/GaAs QWIP NIR AlGaAs/GaAs PIN -2 V S.I. GaAs Substrate LWIR AlGaAs/GaAs QWIP NIR AlGaAs/GaAs PIN Near IR LWIR 77 K 3-Color detector demonstrated, too. Optically-Switched 2-Color Infrared Detector Yong-Hang Zhang (Arizona State) & Elizabeth Steenbergen (AFRL/RXAN)
- 5. 5Distribution A: Approved for public release; distribution is unlimited Speed/Sensitivity Trade-Off of IR Detectors Vladimir Mitin (Buffalo) & Andrei Sergeev (Buffalo) Potential barriers around charged InAs quantum dots (QDs) in GaAs prevents recombination and prolongs electron lifetime Charged QDs strongly enhance IR response of photo-detectors/solar cells p+ GaAs InAs QDs n+ GaAs InAs QDs n+ GaAs n+ GaAs
- 6. 6Distribution A: Approved for public release; distribution is unlimited Electrically Switchable Plasmonic Polarizers Xuejun Lu (Mass-Lowell) Field distribution (resonance wavelength) can be switched by electrically biasing the polarizer RectangularArrayof AuPlasmonicPolarizers
- 7. 7Distribution A: Approved for public release; distribution is unlimited Spectral-Polarization Imaging Viktor Gruev (Washington, St. Louis) Color Filters Angle of Polarization Image SEM of Al Nanowires Si Si Cone Polarization Filter
- 8. 8Distribution A: Approved for public release; distribution is unlimited 0 100 200 300 400 500 600 700 0.0 0.1 0.2 0.3 0.4 Photocurrent(µA) Time(ns) x0.3 PbS QD 2 nm (111) planes (111) planes 0.004 0.006 0.008 0.010 0.012 0.014 1E-5 1E-4 1E-3 0.01 0.1 250 167 125 100 83 71 1E-1 QDDecayRate(ns-1 ) 1E-2 T (K) 1/T ( K-1) Non-radiative Energy Transfer Si Non-radiative Energy Transfer from Quantum Dots Anupam Madhukar (S. Cal.), M. Mahalingam (RXAN) & G. Brown (RXAN) Controlled energy/charge transfer between colloidal nanostructures and conventional semiconductors Substrate QD 10−1 10−2 10−3 10−4 10−5 PhotoluminescenceDecay(/ns) Si
- 9. 9Distribution A: Approved for public release; distribution is unlimited Crystalline Bismuth Nanowire Jimmy Xu (Brown) Bi Pt Bi Pt IR/THz Detector • Bi: only known natural negative index material @ 60um or 5THz • Bi oxides easily • 1st Bi/Pt heterojunction successfully grown
- 10. 10Distribution A: Approved for public release; distribution is unlimited InAs/GaSb Type II Superlattices Sanjay Krishna (New Mexico), Vincent Cowan (RVSS), Christian Morath (RVSS) & John Hubbs (RVSS) Collaboration with Raytheon Vision Systems • Type II superlattices with antimonides barriers can compete with HgCdTe for infrared sensing • Strong interests from AFRL (RX, RY, RV), Army NVL, MDA and DARPA • Enhanced multimodal functionality (color, polarization, dynamic range, phase) through integration with metamaterials Mid-IR Response @ 420 K! GaSb InAs EC EV
- 11. 11Distribution A: Approved for public release; distribution is unlimited Single-Crystal Semimetal/Semiconductor Nano-Composites Chris Palmstrøm (UCSB) & Kurt Eyink (AFRL/RXAN) IncreasingErSbcomposition[001] ρ ˔ ρ// {110} GaSb ErSb GaSb ErSb GaSb(ErSb)x(GaSb)1-x (Semimetal) (Semiconductor) •ErSb/GaSb nano- composites grown by molecular beam epitaxy •Buried conductive layers for multicolor infrared detectors •THz polarizers embedded in III-V heterostructures
- 12. 12Distribution A: Approved for public release; distribution is unlimited Funding Trend I. Adaptive Multimode Sensing – Emphasize tunable detectors and different detection modes such as polarization and phase (in addition to intensity and color). Main challenge: phase detection. II. Novel Infrared Sensors – Emphasize novel materials and structures such as quantum dots, nano- wires, type-II superlattices, and 3D integration. Main challenge: dark current. III.Solar Cells, Thermoelectric Coolers & Others – Deemphasize to focus portfolio with reducing budget.